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use binary tag for binary variables

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This commit is contained in:
Laurent Perron
2022-09-27 18:01:43 +02:00
parent 261020698d
commit cfdb13362d
2 changed files with 16 additions and 3 deletions
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5
ortools/gscip/gscip.cc
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@@ -68,6 +68,8 @@ SCIP_VARTYPE ConvertVarType(const GScipVarType var_type) {
switch (var_type) {
case GScipVarType::kContinuous:
return SCIP_VARTYPE_CONTINUOUS;
case GScipVarType::kBinary:
return SCIP_VARTYPE_BINARY;
case GScipVarType::kImpliedInteger:
return SCIP_VARTYPE_IMPLINT;
case GScipVarType::kInteger:
@@ -82,8 +84,9 @@ GScipVarType ConvertVarType(const SCIP_VARTYPE var_type) {
case SCIP_VARTYPE_IMPLINT:
return GScipVarType::kImpliedInteger;
case SCIP_VARTYPE_INTEGER:
case SCIP_VARTYPE_BINARY:
return GScipVarType::kInteger;
case SCIP_VARTYPE_BINARY:
return GScipVarType::kBinary;
}
}

14
ortools/gscip/gscip.h
View File

@@ -105,7 +105,7 @@ struct GScipLinearRange {
// A variable is implied integer if the integrality constraint is not required
// for the model to be valid, but the variable takes an integer value in any
// optimal solution to the problem.
enum class GScipVarType { kContinuous, kInteger, kImpliedInteger };
enum class GScipVarType { kContinuous, kBinary, kInteger, kImpliedInteger };
struct GScipIndicatorConstraint;
struct GScipLogicalConstraintData;
@@ -159,6 +159,9 @@ class GScip {
// returned variable will have the same lifetime as GScip (if instead,
// GScipVariableOptions::keep_alive is false, SCIP may free the variable at
// any time, see GScipVariableOptions::keep_alive for details).
//
// Note that SCIP will internally convert a variable of type `kInteger` with
// bounds of [0, 1] to a variable of type `kBinary`.
absl::StatusOr<SCIP_VAR*> AddVariable(
double lb, double ub, double obj_coef, GScipVarType var_type,
const std::string& var_name = "",
@@ -185,6 +188,7 @@ class GScip {
double Lb(SCIP_VAR* var);
double Ub(SCIP_VAR* var);
double ObjCoef(SCIP_VAR* var);
// NOTE: The returned type may differ from the type passed to `AddVariable()`.
GScipVarType VarType(SCIP_VAR* var);
absl::string_view Name(SCIP_VAR* var);
const absl::flat_hash_set<SCIP_VAR*>& variables() { return variables_; }
@@ -203,7 +207,13 @@ class GScip {
// ///////////////////////////////////////////////////////////////////////////
// Model Updates (needed for incrementalism)
// ///////////////////////////////////////////////////////////////////////////
// TODO(b/246342145): A crash may occur if you attempt to set a lb <= -1.0 on
// a binary variable. SCIP can also silently change the vartype of a variable
// after construction, so you should check it via `VarType()`.
absl::Status SetLb(SCIP_VAR* var, double lb);
// TODO(b/246342145): A crash may occur if you attempt to set an ub >= 2.0 on
// a binary variable. SCIP can also silently change the vartype of a variable
// after construction, so you should check it via `VarType()`.
absl::Status SetUb(SCIP_VAR* var, double ub);
absl::Status SetObjCoef(SCIP_VAR* var, double obj_coef);
absl::Status SetVarType(SCIP_VAR* var, GScipVarType var_type);
@@ -437,7 +447,7 @@ struct GScipSOSData {
// Models the constraint z = 1 => a * x <= b
// If negate_indicator, then instead: z = 0 => a * x <= b
struct GScipIndicatorConstraint {
// The z variable above.
// The z variable above. The vartype must be kBinary.
SCIP_VAR* indicator_variable = nullptr;
bool negate_indicator = false;
// The x variable above.